1. Field of the Invention
The present invention relates generally to the treatment of bio-oil. More specifically, the invention concerns processes and systems for removing water from bio-oil.
2. Description of the Related Art
With its low cost and wide availability, biomass has increasingly been emphasized as an ideal feedstock in alternative fuel research. Consequently, many different conversion processes have been developed that use biomass as a feedstock to produce useful biofuels and/or specialty chemicals. Existing biomass conversion processes include, for example, combustion, gasification, slow pyrolysis, fast pyrolysis, liquefaction, and enzymatic conversion. One of the useful products that may be derived from the aforementioned biomass conversion processes is a liquid product commonly referred to as “bio-oil.” Bio-oil may be processed into transportation fuels, hydrocarbon chemicals, and/or specialty chemicals.
Despite recent advancements in biomass conversion processes, many of the existing biomass conversion processes produce bio-oils containing high amounts of water. These bio-oils with excess water are not readily miscible with hydrocarbons due to their high polarity and, thus, require extensive secondary upgrading in order to be utilized as transportation fuels, hydrocarbon chemicals, and/or specialty chemicals.
Bio-oils can be subjected to various separation methods in order to remove the excess water. Such separation methods may utilize distillation columns and/or total condensers to condense all the bio-oil and water for separation. However, many valuable water-soluble organic compounds are incidentally removed during these water removal processes, thus decreasing the bio-oil yield. A portion of these water-soluble organic compounds may be subsequently recovered from the removed water, but such processes have proven to be costly and energy inefficient.
Accordingly, there is a need for an improved process and system for removing water from bio-oil that maximizes energy efficiency.